<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>demo1</title>
    <!--显示logo图标-->
    <link rel="shortcut icon" href="../image/logo.png" type="image/x-icon" />
    <script>
        //声明变量
        let msg='hello web19'
        console.log(msg);
        document.write(msg)//1
        document.write('<h1>这是第一次的js课程！<h1>') //2
    </script>
</head>
<body>
    
    hello
</body>
</html>